1. Field of the Invention
The present invention relates to an each area automatic selection receiver for an emergency radio signal, more particularly the present invention relates to an improvement of a receiver capable of automatically establishing an area code in order to automatically receive an emergency radio signal for specific area with a mobile receiver and so forth particularly.
2. Description of the Related Art
Disaster information is mainly issued when extraordinary phenomena in heaven and earth and so forth occur. The disaster information has considerable regional differences caused by the weather, geographical features and so forth. In order to solve the regional differences, not only public broadcast for the general public is performed, but also emergency broadcast for every area is frequently performed. This emergency broadcast firstly transmits area code RAC (Received Area-Code) for specifying signal distributed area before radio broadcasting of this emergency broadcast. When the reception code RAC agrees with an area code AC (Area-code) input in a receiver beforehand, only the receiver is capable of receiving the emergency broadcast. As a result, an alarm announcement is issued and simultaneous reception operation of the receiver is automatically started.
FIG. 2 is a conventional constitution example of an each area automatic selection receiver for an emergency broadcast whose signal distributed area described-above is specified.
Each area emergency broadcasting radio wave is sent to specific area in accordance with an area code. For instance, the administration of the United States of America (NWS) executes Specific Area Message Encoding Service that sends radio wave SAME. The radio wave SAME is an emergency message depending on a code sequence including a digital code determined previously corresponding to characteristic of the message. The receiver A in FIG. 2 selectively receives the each area emergency broadcast radio wave such as the radio wave SAME to output. The receiver A comprises a demodulator 1 for performing demodulation while receiving input radio wave, a decoder 2 for detecting digital data reception message RD included in demodulation output RS and the area code RAC showing signal distribution area of this area code, a area code comparator 4 for comparing this area code with an area code CAC (Current Area Code) in connection with desired reception area that is supplied to be written in a code memory 3, followed by judging agreement thereof in accordance with judgment condition determined beforehand, and an output driver 5 for outputting voice, indication, alarm sound and so forth corresponding to reception message (data) which are supplied from a decoder to exterior while receiving judgment output xe2x80x9cenablexe2x80x9d E of agreement of the area code comparator 4.
In FIG. 2, the automatic selection receiver A is illustrated by dotted line frame. A digital data signal RS is demodulated by the demodulator 1 of the automatic selection receiver A. The demodulated digital data signal RS is input to the decoder 2. The area code RAC and the emergency message signal RD including voice, indication, alarm sound and so forth are obtained from the decoder 2. The area code RAC is input to the area code comparator 4.
On the other hand, also the area code CAC stored in the code memory 3 with manually input is input to the area code comparator 4. The area code CAC is compared with the received area code RAC. When the area code CAC agrees with the area code RAC, output driver 5 turns ON while outputting enable signal. The aforementioned emergency message signal is output.
As is clear described above, in the conventional system, there is no problem in connection with fixed receiver, however, in the equipment that moves over large area such as mobile equipment and so forth, it is necessary to rewrite the area code AC within the code memory in every movement. It is very complicated, there is fear that error writing occurs.
The present invention has been made in consideration of the above-mentioned problem, and an object of the present invention is to provide an automatic selection receiver by area of emergency radio signal in which an area code of desired reception area (current area code) CAC is automatically rewritten even though reception point moves anywhere.
In order to achieve the aforementioned problem, an each area automatic selection receiver of an emergency radio signal of the present invention is a receiver for receiving an each area emergency broadcast electric wave, and the receiver detects an area code of indicating distributed area of a reception message which is in modulation to be output, followed by outputting the reception message when agreeing the detected area code with an established area code of current position where the receiver exists, the receiver includes receiving means for GPS (Global Positioning System) signal, first means for obtaining an established area code of the current position corresponding to the GPS signal, and second means for supplying the established area code to the receiver.
In the present invention, the receiver is made to constitute in such a way that the first means have an area code reference table for converting position data corresponding to reception position obtained from the GPS signal into the established area code, and the second means have a memory for storing the established area code.